PHP obtain form value problem

Question

<input type="text" name="keyword" value ="<?php  echo $_POST['keyword'] ;?>"  required="required">

The code is as shown above

After entering the value in the save form, I use $_Post to get the value, and then output it in value

But when opening the web page, the value is empty, $_POST cannot get anything, and an error will be reported

How to solve it

Answer 1

can be changed to this

<?php echo $_POST['keyword'] ?? '';?>

Answer 2

Declare a variable assignment in the php code and then output it; or use a function to judge (isset)

Answer 3

You are mainly reporting an error because the keyword does not exist

Answer 4

$_POST is used to receive the data submitted by the form. If it is not submitted or the key value does not exist, an error will be reported

Answer 5

Are you sure you passed the value?